Service Programming System

Service programming system (SPS) allows a technician to program a control module through Data Link Connector (DLC). The information transfer circuit used at the DLC is the same serial data circuit used by scan tool for retrieving diagnostic trouble codes (DTCs), displaying data and clearing DTCs. This procedure offers the ability to install software/calibrations matched to a specific vehicle.

Most control modules have 2 types of memory. Learned values such as vehicle identification number, crankshaft variation learned position, software/calibrations identification numbers and control module security information reside in Electrically Erasable Programmable Read Only Memory (EEPROM). This type of memory allows only selected fields of memory to be programmed while the rest of the memory remains unchanged. Flash read only memory has increased memory capacity and allows all programs to be erased and then reprogrammed with updated information.

There are 4 types of control module programming. Remote programming and pass through programming are done when control module is installed in vehicle. Off-board remote programming and off-board pass through programming is done if vehicle is not available or control module is removed from vehicle. An Off-board Programming Adapter (OBPA) is necessary. The Tech 2 or other scan tool, is used as an interface between the vehicle and Techline(R) terminal or a personal computer equipped with General Motors Corporation authorized programming software.

Ensure that before programming a control module:

• There are no charging system concerns.
• The battery voltage is greater than 12 volts but less than 16 volts and a battery charger is not connected to the vehicle battery.
• All systems are turned off that may put a load on the vehicle battery (turn off or disable systems such as daytime running lights by applying the parking brake, heating, ventilation, and air conditioning systems, engine cooling fans, etc.).
• The ignition switch must be in the proper position. The scan tool will prompt you to turn the ignition on, with the engine off (do not change the position of the ignition switch during the programming procedure unless instructed to do so).
• All connections to RS-232 cable, the DLC, Off-board Programming Adapter (OBPA) and voltage supply circuits are secure.
• When performing the pass-through programming procedure using a notebook computer without A/C power adapter, ensure that the internal battery is fully charged.

  After programming a control module, the powertrain may operate slightly different. Operating the powertrain through various driving conditions allows the control module to re-learn certain values. See POWERTRAIN CONTROL MODULE .